For almost seven hours, he watched the changing light pass over the stack, building to a magnificent sunrise and a near-cloudless blue sky – sunny with a slight westerly wind – the most desirable conditions for the demolition.

‘‘I’ll never see anything like this again,’’ said Mr Allen, of Fairy Meadow.

As the sun rose higher, huge crowds formed on vantage points on Military Road, Gallipoli Park, Church Street, Gloucester Boulevard, King George V Park and Third Avenue.

Rob Gansl stood on the roof of his Dovers Drive house to get the best possible view. He would go to his neighbour’s place for a barbecue afterwards, he said, but not necessarily in celebration. He was going to miss the stack.

The stack's last sunrise on the morning of February 20. Picture: SYLVIA LIBER

‘‘It’s a bit like an old friend,’’ he said.

On Church Street – one of the best spots to see the full spectacle side-on – the keenest onlookers brought folding chairs and positioned them so their knees almost pressed against the fencing.

By 9am, the crowd stretched back 100 metres from the exclusion zone.

Someone parked a ute on the side of the road and turned up the radio. It played a sappy song – Robbie Williams’s Feel. A police helicopter passed noisily overhead.

An alert issued by Port Kembla Copper showed the explosion was expected by 10.15am. But the deadline came and went. The crowd’s excitement waned. The radio faded.

Onlookers at the corner of Old Port and Foreshore roads in Port Kembla. Picture: SYLVIA LIBER

By 10.30am, the crowd had grown fidgety. Some children walked along a nearby fence as though it were a tightrope. A dog sat on the bitumen, a dust mask draped around its neck.

Some seagulls flew lazily past the stack, about 200 metres out, and someone in the crowd speculated on how the birds would be surprised by the blast.

The sun beat down, moved higher in the sky. A few wisps of cloud offered no respite. An earlier, gentle breeze had stilled.

A child threw a tantrum in the Unigas station, where people – not cars – were parked beside the shaded bowsers.

The car radio flared again – an announcement – but the message was drowned out by the noises from the sky, where multiple helicopters now circled.

At 11.15.16 am, it happened.

A spattering of explosions – so close together they made almost a single clap – and the end was nigh. The mighty chimney flinched at first, then stopped, seemed to realise the seriousness of its wounds, and began its descent.

On Church Street, there were hoots and cheers and cries to God. Many others watched it in silence, the unchallenged doyenne of the Illawarra skyline, breathtakingly unseated.

From 198 metres up, a few bricks toppled off like crumbs. Puffs of white muck shot up and out of the ventilation holes and then it really was falling – fast.

For a split second it seemed bound no more by bricks or concrete or any obligations of solidness, and looked to bow at its gut.

The view from Kanahooka Point. Picture: CHRISTOPHER CHAN

But the flexibility was only an illusion as the middle tore irreparably apart.

Just before the pieces disappeared behind the skyline, its tip disconnected and flew off in a plume of muck.

A beat, two beats – maybe three – then a fresh cumulus bloomed and a shuddering, deadened thud marked the end of it.